Jarcho–Levin syndrome is an eponym that refers to a group of conditions characterized by short trunk dwarfism, rib and vertebral anomalies, and normal long bones. The name Jarcho–Levin syndrome was attached to the condition because of an initial report in 1938 by Saul Jarcho and Paul Levin who described a brother and sister with severe malformations of their vertebral columns. In addition, the mother of these children had a minor cervical vertebral anomaly. The infants demonstrated a shortened thorax and a prominent abdomen. Both infants died from respiratory failure during the first year of life.

Subsequently, the classification of genetic syndromes that include rib and vertebral anomalies as their major symptoms has become progressively more confusing. Jarcho and Levin’s original disorder was termed “hereditary malformation of the vertebral bodies.” Related or identical conditions have also been called familial dwarfism due to hereditary multiple hemivertebrae, spondylothoracic dysostosis, spondylocostal dysplasia, spondylocostal dysostosis, costovertebral dysplasia, and occipito-facial-cervical-thoracic-abdominal-digital dysplasia. The nosology of these various conditions is further complicated by the fact that some of them are inherited as autosomal dominant genes and some are associated with autosomal recessive inheritance (Table 96-1). The condition that most clinicians agree is the classical presentation of Jarcho–Levin syndrome is spondylothoracic dysplasia, and consists of multiple rib and vertebral anomalies associated with a “crab-claw” or “fanlike” configuration of the ribs on X-ray (Figures 96-1 and 96-2), with a resultant small thoracic volume and symptoms coincident with respiratory insufficiency. The majority of patients who manifest the classic Jarcho–Levin syndrome can trace their ancestry to Puerto Rico (Perez-Comas and Garcia-Castro, 1974).

The incidence of spondylothoracic dysplasia is unknown. It is rare. As previously stated, the disorder occurs most frequently in patients of Puerto Rican ancestry, although there have been multiple reports of familial Jarcho–Levin syndrome in Europeans and at least one report in an Arab family (Romeo et al., 1991; Eliyahu et al., 1997). The incidence of spondylocostal dysplasia is 0.25 per 10⁵ livebirths (Martínez-Frías et al., 1994).

Spondylothoracic dysostosis should be suspected in any fetus with multiple vertebral anomalies and spina bifida (Cornier et al., 2003). Jarcho–Levin syndrome has been diagnosed in the first trimester through a combination of increased nuchal translucency thickness and spine abnormalities visualized by two-dimensional or three-dimensional sonography (Hull et al., 2001; Kauffmann et al., 2003).

The fetal vertebral bodies can be visualized between 16 and 20 weeks of gestation on a longitudinal section that includes the entire spinal canal. At this point in the pregnancy, the normal parallel line configuration of the fetal spine should be obtainable no matter where the fetal spine is located within the uterus (Miskin et al., 1979). The first prenatal roentgeno-graphic diagnosis of Jarcho–Levin syndrome was made in 1979 and the first prenatal sonographic diagnoses were made in the 1980s (Marks et al., 1989). In 1987, Tolmie et al. described a Scottish couple who had a previous child affected with Jarcho–Levin syndrome. In a subsequent pregnancy, at 20 weeks of gestation, a grossly deformed spine and incomplete rib cage were demonstrated on prenatal sonography. The pregnancy was electively terminated and postmortem study revealed associated anomalies, including an imperforate anus and ectopic adrenal glands. Simultaneously, another report at 22 weeks of gestation described the subtle spacing and widening of the fetal vertebrae seen in prenatal sonographic examination of a fetus with Jarcho–Levin syndrome. At 22 weeks of gestation, a slightly smaller than normal chest diameter was appreciated but the diagnosis was unclear. By 28 weeks of gestation, an abnormally shaped chest was appreciated that included slight flattening of the ribs and irregularly spaced vertebrae (Apuzzio et al., 1987). In the third report, a fetus at 23 weeks of gestation was described with a shortened spine, disorganization of the vertebral bodies, posterior fusion of the ribs, with a short thorax but normal thoracic diameter. In a coronal view, narrowing of the lateral laminae in the lower thoracic and upper lumbar region was described. In the sagittal and coronal planes, grossly malaligned vertebrae, disorganization of vertebral bodies, and posteriorly fused ribs were appreciated (Romero et al., 1988). In 1989, Marks et al. reported two fetuses with sonographic findings of Jarcho–Levin syndrome. They described the following sonographic criteria for diagnosis of this condition (Marks et al., 1989):

1. 
   

   Unpaired and poorly formed vertebral centers resulting in a “pebblelike” appearance of the spine (Figure 96-3);

   
   
2. 
   

   Multiple vertebral body fusion causing an irregular shortened spine;

   
   
3. 
   

   Indistinct or joined ribs posteriorly;

   
   
4. 
   

   A small or shortened thorax;

   
   
5. 
   

   A protuberant abdomen resulting from the shortened thorax;

   
   
6. 
   

   The presence of abdominal hernias;

   
   
7. 
   

   Normal amniotic fluid volume;

   
   
8. 
   

   Normal limb length and biparietal diameter measurements for gestational age.

Subsequent reports have described the utility of prenatal sonographic diagnosis in families known to be at risk because of the prior birth of an affected infant (Lawson et al., 1997; Wong and Levine, 1998). In one study, four affected fetuses were diagnosed as early as 12 weeks of gestation (Eliyahu et al., 1997).